Floor cleaning apparatus with control circuitry

ABSTRACT

A floor cleaner is provided for cleaning a floor, where the floor cleaner has a front and a rear and includes: a sweeper for sweeping the floor; a scrubber, connected to the sweeper and located in the rear of the sweeper, for wetting and cleaning the floor; and a burnisher, connected to the scrubber and located in the rear of the scrubber, for burnishing the floor.

RELATED APPLICATIONS

This application claims priority of U.S. Provisional Application Ser.No. 60/138,179 filed Jun. 8, 1999.

FIELD OF THE INVENTION

This invention relates to floor cleaning systems or cleaners forcleaning floors such as waxed floor surfaces including Vinyl CompositionTile (VCT) floors with a glossy polymeric finish such as an Ultra HighSpeed (UHS) commercial finish.

BACKGROUND OF THE INVENTION

Modern resilient and hard flooring materials are often coated withpolymer coatings which may be natural or synthetic polymers, sometimesreferred to as “floor waxes”. These coating materials can impart varioustypes of finish to the floors. Acrylic polymers are often used on suchfloors where a transparent, glossy finish is desired. Followingapplication of the coating materials, the floor must be periodicallyswept, scrubbed and polished to restore the shine worn by foot and othertraffic on the floor. For glossy floors, the burnishing and otheroperations may be performed daily.

Cleaning of polymer coated resilient and hard floor materials hastraditionally comprised the operations of sweeping, scrubbing andburnishing. These operations are generally performed separately in therecited order. The coated floor is initially swept or dust mopped toremove dust and larger debris particles so that they Will not be actedupon by the scrubbing and/or burnishing steps that follow and causediscoloration or damage to the floor coating. After sweeping, the flooris cleaned by scrubbing with water and other additives such as soaps,surfactants and the like and left to dry under ambient conditions, withor without bulk liquid being first removed by a squeegee operationseparate from, or in conjunction with, the scrubbing operation. Afterscrubbing, the dry floor coating may be burnished with a burnishingdevice to provide a luster or shine to the coating surface which is anappearance often desired in commercial buildings The burnisher istypically a propane powered device which rotates a flat, circularpolishing pad at relatively high speed to polish the floor coating.

The above operations have generally been performed manually in threeseparate steps. More recently, mechanical, powered sweepers, scrubbersand burnishers have become available. Often a single operator willperform the operations serially.

SUMMARY OF THE INVENTION

The present inventors have discovered that performing the burnishingoperation with one or more of the sweeping and/or scrubbing operationsis advantageous. Combining the scrubbing and burnishing operations, in aunitary, coordinated method or system so that the operations areperformed serially, but closely spaced in time, is particularlydesirable and provides certain advantages not previously achieved orrecognized.

In addition, a preferred embodiment of the present invention includes atleast scrubbing and burnishing, and most preferably all threeoperations, in a single unitary device with logical electronic andmechanical controls that allow a single operator to easily manipulateall of activities of the floor cleaning operations simultaneously. Thispermits all three traditional operations to be performed with a singlepass of the floor cleaning device over a given floor area. Advantagesinclude the saving of labor and time as well as ensuring that theburnishing operation will never be performed on an unclean floor whichcould result in forcing the soil into the surface causing discolorationor severe damage to the coating surface. More surprisingly, the presentsystem provides enhanced performance compared to the conventionaloperations performed serially at widely spaced intervals using separatedevices. More particularly, the burnishing operation provides enhancedresults, such as increased gloss, when performed closely following thescrubbing operation.

In a presently preferred embodiment of the invention, the systemcomprises a mechanical structure wherein each of the selected cleaningoperations is included in a single device having a unitary structure foroperation by a single operator. Alternatively, the system may be a“train” of devices coordinated mechanically or electronically by asingle operator. An important feature is that the scrubbing andburnishing operations be performed in the desired order and in closeproximity in time while the coating is in a deformable, plastic state.

As used in this application, the term “coating” or “wax” refers towidely used polymeric coating materials which are applied to arelatively smooth natural or synthetic resilient or hard flooringmaterial, such as vinyl tile or natural stone or other synthetic, hardor resilient materials. Typically these coatings comprise one or morenatural and/or synthetic polymers, such as the hard Carnauba waxes, or amixture of materials containing a synthetic polymer such as an acrylicpolymer. The coating should be solid at room temperature and transparentand hard enough to provide protection for the underlying flooring andstand up to pedestrian traffic. Because these coatings can be damaged ormarked during use, such surfaces are typically maintained by periodicsweeping, wet scrubbing and/or burnishing. The acrylic polymer coatingsare preferred for floors that are maintained in a high gloss state.

As used in this application, the term “sweeping” refers to a dryoperation involving removing dust and larger particles from a floorsurface such as by dust mopping, brushing, vacuuming or blowing or thelike so that loose soil particles and other materials are not presentduring the scrubbing or burnishing operations where their presence couldinhibit the cleaning or burnishing or cause a discoloration of thecoating or other physical damage to the floor surface during the moreaggressive scrubbing and burnishing operations.

The term “scrubbing” as used with respect to this invention refers to awet operation involving the application of water and/or other commoncleaning compositions to a coated floor surface together with scrubbingthe floor surface with mops, rotating pads or brushes or other cleaningtools. In the present invention it has been discovered that acylindrical brush having relatively soft, synthetic polymeric bristlesis preferred which may be rotated at speeds of from about 500 to 2000rpm. The scrubbing operation may also involve removal of bulk surfaceliquid from the floor following scrubbing, such as by evaporation,vacuuming or a mechanical squeegee operation or a combination thereof.

The term “burnishing” as used herein means the relatively high-speedpolishing of the coating surface of the floor after scrubbing to providea glossy, reflective surface. Modem burnishing tools generally comprisean electric or gas or liquid fuel powered machine for rotating a flat,circular fibrous pad at relatively high speed (for example 1000 to 4000rpm) to polish the surface.

The “gloss” of the coating is measured by a gloss meter which directs abeam of light normal to the surface of the floor and measures thereflection of the light at angles of 20 degrees and/or 60 degrees fromnormal. The percentage of the light reflected is reported as the “gloss”of the floor coating. A difference of 5 points on the gloss meterrepresents a difference which can be perceived as significant by thehuman eye.

In one general aspect, the invention features a floor cleaner forcleaning a floor, where the floor cleaner has a front and a rear andincludes: an optional sweeper for sweeping the floor; a scrubber,connected to the sweeper and located in the rear of the sweeper, forwetting and cleaning the floor; and a burnisher, connected to thescrubber and located in the rear of the scrubber, for burnishing thefloor.

Embodiments of this aspect of the invention may include one or more ofthe following features.

The cleaner is sized to operate within aisles having dimensions greaterthan or equal to about 24 inches.

The sweeper includes two counter-rotating brushes, one or both of whichis driven by a motor. The brushes are positioned relative to one anothersuch that bristles of the brushes overlap. The sweeper includes a hopperspaced from the brushes, and a ramp which is connected to the hopper andlocated between the brushes and the hopper. A portion of the ramp islocated under a portion of the brushes. A portion of the ramp is curvedupwardly along an axis extending from the brushes to the hopper. Thebrushes are mounted on the frame for retraction substantially along avertical axis.

The scrubber includes a scrubber brush which has an axis of rotationsubstantially parallel to the floor and substantially perpendicular toan axis running from the front to the rear of the cleaner. The scrubberbrush includes 0.15 mm diameter polymeric bristles. The scrubber ispivotally mounted on the frame for retraction.

A cleaning liquid dispenser dispenses cleaning liquid. The cleaningliquid dispenser includes a liquid dispensing trough positionedsubstantially parallel to the axis of rotation of the scrubber brush andis substantially coextensive with the scrubber brush. The liquiddispensing trough has at least one opening for dispensing a cleaningliquid.

The scrubber includes a member which is mounted for movement from afirst position to a second position. In its first position, the memberprevents cleaning liquid from the scrubber brush to fall on the floor.In its second position, the member prevents the cleaning liquid from thescrubber brush to splash against at least a portion of the cleaner. Themember extends along the length of the scrubber brush and is rotatablebetween the first and second positions around a second axissubstantially parallel to the axis of rotation of the scrubber brush.

A squeegee blade is positioned in the rear of the scrubber brush along asecond axis parallel to the axis of rotation of the scrubber brush. Avacuum source applies Suction to a portion of the floor in front of thesqueegee blade to collect liquid gathered by the squeegee blade. Asecond squeegee blade is positioned in front of, and spaced apart from,the first-mentioned squeegee blade. The vacuum source applies thesuction to the space between the first-mentioned and the second squeegeeblades.

A cleaning liquid system includes the vacuum source, the cleaning liquiddispenser, a chamber for separating the cleaning liquid from a mixtureof air and cleaning liquid collected by the suction applied to the floorby the vacuum source, and a filter for filtering out dirt from theseparated cleaning liquid prior to dispensing the separated cleaningliquid by the cleaning liquid dispenser. The chamber is shaped and sizedto reduce a velocity of a flow of the mixture of air and cleaning liquidto separate the cleaning liquid from the mixture of air and cleaningliquid. A squeegee mount houses one or both of the squeegee blades,where the squeegee mount includes grooves for slidably mounting thesqueegee blades. The grooves are typically key-hole shaped, and portionsof the squeegee blades may be key-shaped and sized to fit in thegrooves. The squeegee mount defines a cavity between the first andsecond grooves, at one end the cavity opening to the space between thesqueegee blades and at another end connecting to a vacuum source. Thesqueegee mount is pivotally mounted on the frame for verticalretraction.

The burnisher and scrubber are positioned relative to one another suchthat a front-most point of a burnisher pad of the burnisher is locatedbetween 10 cm and 40 cm from a rear-most point of contact of thescrubber brush to the floor. The burnisher pad includes a burnishing padand a motor for spinning the burnisher pad. The burnisher is mounted onthe frame for vertical retraction substantially along a vertical axis.The burnisher is mounted on the frame by a four bar linkage whichfloatingly supports the burnisher pad near the floor during operation.

The cleaner has a drive wheel, and a motor which is disengagably coupledto the drive wheel and drives the drive wheel. A control circuitrycontrols a velocity of the drive wheel by measuring the velocity,comparing the measured velocity to a selected velocity, and adjustingthe velocity of the drive wheel based on a result of the comparison.

In another general aspect, the invention features a floor cleaner forcleaning a floor which includes: a scrubber for wetting and cleaning thefloor; and a member being mounted for movement from a first position toa second position, where in the first position the member preventscleaning liquid from the scrubber brush to fall on the floor and in thesecond position the member prevents the cleaning liquid from thescrubber brush to splash against at least a portion of the cleaner.

In yet another general aspect, the invention features a cleaner whichincludes a scrubber for wetting and cleaning the floor, a squeegeeblade, and a squeegee mount for housing the squeegee blade, where thesqueegee mount includes a groove for slidably mounting the squeegeeblade.

In yet another general aspect, the invention features a cleaner forcleaning a floor, where the cleaner includes: a first assembly ofcomponents for performing a first cleaning operation on the floor; asecond assembly of components for performing a second cleaning operationon the floor; and control circuitry, connected to the first and secondassemblies, executing in parallel a first program module operating thefirst assembly and a second program module operating the secondassembly.

Embodiments of this aspect of the invention may include one or more ofthe features below.

The first program supplies data to the second program, and the secondprogram modifies the operation of the second assembly based on the data.

The control circuitry comprises at least two processors, one processorexecuting the first program and the second processor executing thesecond program.

The first assembly includes a scrubber and the second assembly includesa sweeper.

The cleaner includes a third assembly of components for burnishing thefloor, where the control circuitry is further connected to the thirdassembly and executes, in parallel with the first and second programmodules, a third program module operating the third assembly.

In one other general aspect, the invention features a cleaner forcleaning a floor, where the cleaner includes: a first assembly ofcomponents for performing a first cleaning operation on the floor; asecond assembly of components for performing a second cleaning operationon the floor; control circuitry, connected to the first and secondassemblies, executing in parallel a first and second program modules;where the first program module includes a first plurality ofinstructions for controlling the operations of the first and secondassemblies and coordinating among the operations of the first and secondassemblies and the second computer program module includes a secondplurality of instructions for controlling the operations of the firstand second assemblies; where the first plurality of instructionsincludes an instruction for supplying a command from the first programmodule to the second program module, the command requiring performanceof a sequence of actions by at least one of the first and secondassemblies, where the first program module, after executing theinstruction for supplying the command, executes other instructionsindependent of performance of the sequence of actions; and where thesecond plurality of instructions includes a sequence of instructions forcausing the at least one of the first and second assemblies to performthe sequence of actions, the second program module executing thesequence of instructions independent of the first program module.

Embodiments of this aspect of the invention may include one or more ofthe following features.

The control circuitry has at least two processors, one processorexecuting the first program module and the second processor executingthe second program module. The first assembly includes a scrubber andthe second assembly includes a sweeper.

The cleaner has a third assembly of components for burnishing the floor,where the control circuitry is further connected to the third assembly.The first program module further includes a third plurality ofinstructions for operating the third assembly and coordinating among theoperations of the third assembly, and the first and second assemblies.The second computer program module includes a fourth plurality ofinstructions for operating the third assembly. The second plurality ofinstructions includes an instruction for supplying a second command fromthe first program module to the second program module, the commandrequiring performance of a second sequence of actions by the thirdassembly, where the first program module, after executing theinstruction for supplying the second command, executes otherinstructions independent of performance of the second sequence ofactions. The second plurality of instructions includes a second sequenceof instructions for causing the third assembly to perform the secondsequence of actions, the second program module executing the secondsequence of instructions independent of the first computer programmodule.

In another general aspect, the invention features a cleaner whichincludes: a first assembly of components for performing a first cleaningoperation; a second assembly of components for performing a secondcleaning operation; and control circuitry, connected to the first andsecond assemblies, coordinating an operation of the first assemblyrelative to an operation of the second assembly based on a distancetraveled by the cleaner.

Aspects of the invention may be implemented in hardware or software, ora combination of both. Preferably, these aspects are implemented incomputer programs executing on programmable computers that each includea processor, a storage medium readable by the processor (includingvolatile and non-volatile memory and/or storage elements). Program codeis applied to data entered through the input device to perform thefunctions described above and to generate output information. The outputinformation is applied to one or more output devices.

Each program is preferably implemented in a high level procedural orobject oriented programming language to communicate with a computersystem. However, the programs can be implemented in assembly or machinelanguage, if desired. In any case, the language may be a compiled orinterpreted language.

Each such computer program is preferably stored on a storage medium ordevice (e.g., ROM or magnetic diskette) that is readable by a general orspecial purpose programmable computer for configuring and operating thecomputer when the storage medium or device is read by the computer toperform the procedures described in this document. The system may alsobe considered to be implemented as a computer-readable storage medium,configured with a computer program, where the storage medium soconfigured causes a computer to operate in a specific and predefinedmanner.

Other features and advantages of the invention will become apparent fromthe following description of preferred embodiments, including thedrawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top, rear perspective view of a cleaner;

FIG. 2 is a top, front perspective view of the cleaner with its housingremoved;

FIG. 3 is a cross-sectional view of the cleaner with its sweeper,scrubber, and burnisher assemblies in lowered positions;

FIG. 3A is a cross-sectional view of the cleaner with its sweeper,scrubber and burnisher assemblies in retracted positions;

FIG. 4 is a perspective view of the sweeper assembly of the cleaner;

FIG. 4A is a cross-section view of a portion of the sweeper assembly;

FIG. 5 is another perspective view of the sweeper assembly with itshopper removed;

FIG. 6 is a cross-sectional view of the sweeper assembly;

FIG. 7 is a top perspective view of the scrubber assembly of thecleaner, with an end plate removed for clarity;

FIG. 8 is a bottom perspective view of the scrubber assembly with itssplash and drip guard in a lowered position;

FIG. 9 is a cross-sectional view of the scrubber assembly with itssplash and drip guard in a retracted position;

FIG. 9A is a cross-sectional view of the scrubber assembly with itssplash and drip guard in its lowered position;

FIG. 10 is a top perspective view of the scrubber assembly;

FIG. 11 is a perspective view of a liquid dispenser of the scrubberassembly;

FIG. 12 is a perspective view of a squeegee assembly of the scrubberassembly;

FIG. 12A is a perspective view of the squeegee assembly with one of itssqueegee blades partially removed;

FIG. 13 is a cross-sectional view of the squeegee assembly;

FIG. 14 is a perspective view of a fluid and vacuum system of thecleaner;

FIG. 14A is a top view of the fluid and vacuum system;

FIG. 15 is a cross-sectional view of the fluid and vacuum system;

FIG. 16 is another cross-sectional view of the fluid and vacuum system;

FIG. 17 is a perspective view of a burnisher assembly of the cleaner;

FIG. 18 is a top view of the burnisher assembly;

FIG. 19 is a cross-sectional view of the burnisher assembly;

FIG. 20 is a schematic diagram of a control system of the cleaner;

FIG. 21 is a behavioral diagram of an application program executed bythe control system;

FIG. 22 is the pseudocode for the steps taken by an error behaviormodule of the application program;

FIG. 23 is the pseudocode for the steps taken by a control behaviormodule of the application program;

FIG. 24 is the pseudocode for the steps taken by a handle behaviormodule of the application program;

FIG. 25 is the pseudocode for the steps taken by an enable behaviormodule of the application program;

FIG. 26 is the pseudocode for the steps taken by a sweep behavior moduleof the application program;

FIG. 27 is the pseudocode for the steps taken by a scrub behavior moduleof the application program;

FIG. 28 is the pseudocode for the steps taken by a drive behavior moduleof the application program;

FIG. 29 is the pseudocode for the steps taken by a distance behaviormodule of the application program; and

FIG. 30 is the pseudocode for the steps taken by a burnish behaviormodule of the application program.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1, 2, 3, and 3A, a cleaner 10 typically includes asweeper assembly 12, a scrubber assembly 14, and a burnisher assembly16, each of which is mounted on a common frame 18. In one embodiment,cleaner 10 may only include scrubber assembly 14 and burnisher assembly16. Cleaner 10 also includes a housing 20 which is fastened to frame 18.Cleaner 10 is preferably sized to fit in aisles of typical retail storessuch as grocery stores and department stores. Such aisles typically havewidths greater than or equal to about 24 inches, and more typicallyranging from about 39 to about 72 inches.

Cleaner 10 further includes a vacuum and cleaning liquid subsystem 30 towhich scrubber assembly 14 is connected. Vacuum and liquid subsystem 30is responsible for depositing a cleaning liquid on a scrubber brush ofscrubber assembly 10 and recovering the deposited liquid from the floor.Cleaner 10 also includes batteries 32 which supply power to the variouscircuits and motors in cleaner 10, including two motors 64 driving aright drive wheel 28 and a left drive 28B for moving cleaner 10 invarious directions.

Housing 20 has a control panel 22 which can be used by a user to operatecleaner 10. The controls on control pad 22 provide the user with theoption of choosing to sweep, scrub, burnish, or perform any combinationof these three cleaning operations including performing all threecleaning operations at once. The controls on control pad 22 also includean emergency stop button which the user can use to stop all cleaningoperations and movements of cleaner 10 in the case of an emergency. Thecontrols further include a speed and direction selector which allows theuser to select among two forward speeds and one reverse speed. Thecontrols further include a key switch for turning cleaner 10 on and off.A series of LEDs on control panel 22 indicate to the user which cleaningfunctions are being currently performed.

Cleaner 10 also includes a handle 24 having right and left pressuresensing pads 26A-B. The user can use these pads to control the directionof travel of cleaner 10 by directly controlling the speed of rotation ofdrive wheels 28A-B. The user can make cleaner 10 turn right byselectively applying pressure to right pressure sensing pad 26A ratherthan to left pressure sensing pad 26B. Similarly, the user can makecleaner 10 turn left by applying pressure to left pressure sensing pad26B rather than to right pressure sensing pad 26A. By pressing bothpressure sensing pads 26A-B, the user can make cleaner 10 travel forwardin a straight line. The user can stop cleaner 10 by removing both handsfrom pressure sensing pads 26A-B for a predetermined period of time.

Pressure sensing pads 26A-B and the controls on the control panel 22supply control signals to a control subsystem 34 (schematically shown inFIG. 20) which, in accordance with those signals, operate cleaner 10.Control subsystem 34, among other things, includes software forautomatically controlling the various cleaning operations of cleaner 10.The application programs are designed to improve the quality of cleaningoperations and reduce the risk of damage to the floor by ensuring thatcleaning operations are performed in particular sequences. For example,when the user selects performing all three cleaning operations at thesame time, the application programs ensure that the burnisher assembly16 does not burnish a floor surface which has not already been scrubbedby scrubber assembly 14. Additionally, when the user selects to stop allcleaning operations, the application programs ensure that as much aspossible the deposited cleaning liquid is collected from the floorsurface prior to stopping all cleaning operations.

Having briefly described the structure and operation of cleaner 10, wewill now describe in detail the structure and operation of each of thesubsystems of cleaner 10. These subsystems are, in the order they willbe described: drive wheels 28A-B, sweeper assembly 12, scrubber assembly14, burnisher assembly 16, vacuum and cleaning liquid subsystem 30, andcontrol subsystem 34.

Drive Wheels

Referring specifically to FIG. 2, each one of drive wheels 28A-B isdriven by a dedicated DC servo motor 64 through gear and chain mechanism66 (only the mechanism for drive wheel 28A is shown). Each one of servomotors 64 is controlled by control system 34. Each one of drive wheels28A-B can be disengaged from its motor 64 by turning a knob 68 on thatdrive wheel. Drive wheels 28A-B may also be located between burnisherassembly 16 and scrubber assembly 14, especially when sweeper assembly12 is absent to provide a pivot point for cleaner 10 making it easierfor the operator to handle and to negotiate sharp turns.

Sweeper Assembly

Referring to FIGS. 4, 4A, 5, and 6, sweeper assembly 12 includes twocounter-rotating brushes 36A-B, each of which is respectively driven byone of DC servo motors 38A-B. Motors 38A-B are connected to a DC servomotor driver in control subsystem 34, which will be described in furtherdetail below. Brushes 36A-B and motors 38A-B are mounted on a sweeperframe 40. Brushes 36A-B are located relative to one another such thattheir bristles overlap by approximately 0.5 inch. Sweeper assembly 12also includes a hopper 42 and a ramp 44 connected to hopper 42. Ramp 44has a solid metal portion 46 and a pliable, plastic portion 48. Solidportion 46 has a curved profile as shown in FIG. 6. Since plasticportion 48 is pliable, when plastic portion 48 comes into contact withthe floor surface, it will less likely scratch or otherwise damage thefloor surface.

Hopper 42 has four pegs 50 on an upper portion of its side walls 42A-B.To amount hopper 42 onto sweeper frame 40, hopper 42 is slid in betweenmotors 38A-B and into an opening defined by sweeper frame 40 until eachone of pegs 50 is aligned with a corresponding one of detentes 52.Hopper 42 is then lowered until each one of pegs 50 rests in thecorresponding one of detentes 52 (best shown in FIG. 5). To removehopper 42, hopper 42 is lifted up until pegs 50 are clear of detentes52. Hopper 42 is then slid out of sweeper frame 40. Hence, hopper 42 canbe easily removed to be emptied, and then can be easily placed back insweeper frame 40.

Sweeper assembly 12 includes a mounting frame 54 for mounting thesweeper assembly onto frame 18 of cleaner 10 (shown in FIGS. 1-2).Mounting frame 54 is connected to sweeper frame 40 by a four bar linkage56. Four bar linkage 56 has four horizontal members 56A-D, each one ofwhich is pivotally connected at one end to mounting frame 54 and atanother end to sweeper frame 40. Four bar linkage 54 allows sweeperframe 40 and components attached to sweeper frame 40 to be retracted andlowered substantially along a vertical axis.

The mechanism for retracting and lowering sweeper frame 40 includes a DCservo motor 58 coupled to an off-center cam 60 which is rotatablycoupled to a peg 62 of sweeper frame 40 (best shown in FIG. 4A). Motor58 is connected to a DC servo motor driver controlled by controlsubsystem 34, as will be described in further detail below. As motor 58rotates cam 60, cam 60 either lifts or lowers peg 62 and therebyretracts or lowers sweeper frame 40. FIGS. 3-3A show sweeper assembly 12in its lowered and retracted positions.

Referring particulariy to FIG. 6, during operation, motors 38A-B causebrushes 36A-B to rotate at about 30 to 100 RPM. Sweeper assembly 40,together with brushes 36A-B and ramp 44, are then lowered until brushes36A-B come into contact with the floor. Brushes 36A-B sweep the debrisin front of the brushes towards where brushes 36A-B overlap one anotherover the middle of ramp 44. There, brushes 36A-B catch the debrisbetween their bristles and push the debris up ramp 44. The debristravels over curved portion 46 where the debris gains an upward momentumcausing the debris to be effectively thrown into hopper 42.

Scrubber Assembly

Referring to FIGS. 7-9, 9A, and 10, scrubber assembly 14 includes ascrubber brush 80 rotatably mounted in a scrubber frame 90. Scrubberbrush 80 has a horizontal axis of rotation substantially parallel to thefloor surface and substantially perpendicular to the direction of travelof cleaner 10 during operation. Because scrubber brush 80 has ahorizontal axis of rotation, it occupies a relatively small space,thereby allowing cleaner 10 to have components for performing threecleaning operations, that is, sweeping, scrubbing, and burnishing. Forexample, scrubber brush 80 has bristles which are polymeric bristles,preferably, having a diameter of about 0.15 mm.

Scrubber frame 90 is constructed out of a number of segments, and ispivotally connected to a mounting frame 92 by bolts 94. Mounting frame92 is in turn mounted onto frame 18 of cleaner 10 (shown in FIGS. 1-2).A DC servo motor 106 is provided for rotating housing 90 about bolts 92.Motor 106 is connected to a gear 106A which engages a wedge-shaped gear108 bolted to scrubber frame 90. As motor 106 rotates gear 106A and gear108, gear 108 acts as a lever and rotates housing 90 about bolts 94.Motor 106 is connected to a DC servo motor driver controlled by controlsubsystem 34, as will be described in further detail below.

Scrubber brush 80 is spun about its axis of rotation by a DC servo motor86 through a belt and pulley mechanism. The belt and pulley mechanismconsists of a pulley 82 connected to scrubber brush 80, a pulley 88connected to motor 86, and a belt 84 looped over pulley 82 and pulley88. Motor 86 is mounted on scrubber frame 90. Motor 86 is connected toDC servo motor driver in control subsystem 34, as will be described infurther detail below.

A splash and drip guard 96 extends the length of scrubber brush 80.Splash and drip guard 96 is rotatably mounted onto scrubber frame 90 andis rotatable around the axis of rotation of scrubber brush 80. Whensplash and drip guard 96 is retracted (as shown in FIGS. 7 and 9),splash and drip guard 96 prevents cleaning liquid from a rotatingscrubber brush 80 to splash against the inside of cleaner 10. When inits lowered position (as shown in FIGS. 8 and 9A), splash and drip guard96 prevents cleaning solution from scrubber brush 80 to drip onto thefloor.

The mechanism for lowering and retracting splash and drip guard 96includes a geared lip 100 on splash and drip guard 96 and a gear 102.Gear 102 is driven by a motor 104 (shown in FIG. 10) which is connectedto a DC servo motor driver controlled by control subsystem 34, as willbe described in further detail below. When motor 104 rotates gear 102,gear 102 causes geared lip 100 and hence splash and drip guard 96 torotate about the axis rotation of scrubber brush 80.

Referring also to FIG. 11, a cleaning solution dispenser 110 has atrough portion 112 into which cleaning solution is poured through anopening 114 in scrubber frame 90. A pipe (not shown) connects opening114 to vacuum and liquid subsystem 30. Trough portion 112 of cleaningsolution dispenser 110 includes a number of evenly spaced holes 116which dispense cleaning solution evenly onto scrubber brush 80 along itslength. Cleaning solution dispenser 110 also includes an integratedsplash guard portion 118 protecting components of cleaner 10.

Also referring to FIGS. 12, 12A and 13, scrubber assembly 14 alsoincludes a squeegee assembly 120. Squeegee assembly 120 has a squeegeecore 122 that is mounted onto left and right connecting members 138A-B.Connecting members 138A-B are pivotally mounted on mounting frame 92.Squeegee core 122 of squeegee assembly 120 has two key hole shapedgrooves 124A-B which extend along the length of squeegee core 122.Grooves 124A-B are sized and shaped to receive squeegee blades 126A-B.Squeegee blades 126A-B have an upper portion which is key shaped and issized to fit in the key-hole shaped grooves 124A-B. By key-hole shapedgrooves, we refer to a groove which has a portion that is wider, ordifferently shaped, than at least one other portion of the groove, sothat a properly sized and shaped key-shaped component inserted thereinwill resist a downward pulling force because of its shape and remains inthe groove. To insert squeegee blades 126A-B into grooves 124A-B,squeegee blades 126A-B are slid along the length of grooves 124A-B. Itshould be noted that squeegee blade 126A, which is the leading squeegeeblade, is ribbed so as to allow cleaning liquid collected in front ofsqueegee blade 126A to flow into the space between squeegee blades126A-B to be collected by suction from vacuum and liquid subsystem 30.

At one end of grooves 124A-B, a cover 128 is bolted on squeegee core 122for preventing squeegee blades 126A-B from sliding out of squeegee core122. At the other end of grooves 124A-B, a cover 130 is pivotallymounted on squeegee core 122. Cover 130 is held in place over the grooveopenings by a spring loaded ball and detente mechanism 132.

Squeegee assembly 120 has a pair of wheels 140A-B which are installed onconnecting members 138A-B, respectively. Wheels 140A-B rest on the floorsurface during operation and prevent the weight of squeegee assembly 120from crushing squeegee blades 126A-B.

Referring particularly to FIG. 13, squeegee assembly 120 furtherincludes a vacuum plenum 134 mounted on squeegee core 122. Vacuum plenum134 defines a cavity 142 which is continuous with a cavity 144 insqueegee core 122. Cavity 144 is located between grooves 124A-B. At thebottom of squeegee core 122, cavity 144 runs substantially the length ofsqueegee core 122 and opens into the space between squeegee blades126A-B. Plenum 134 further includes a pipe 136 which connects to avacuum hose (not shown) which leads to vacuum and liquid subsystem 30.

For lifting squeegee assembly 120, a bracket 146 is provided on squeegeeassembly 120. A portion of bracket 146 rests on an off-center cam 148which is coupled to a DC servo motor 150 is connected to a DC servomotor driver controlled by control subsystem 34, as will be described infurther detail below. As motor 150 rotates cam 148, bracket 146 islifted thereby lifting squeegee assembly 120.

During operation, vacuum and liquid subsystem 30 pumps cleaning liquidinto trough portion 112. The pumped cleaning liquid falls onto scrubberbrush 80 through openings 116 of trough portion 112. Then, scrubberbrush 80, wet with cleaning liquid, is lowered to scrub the floor.

Suction from vacuum and liquid subsystem 30 creates a negative airpressure in cavities 142 and 144, and in the space between squeegeeblades 126A-B. This negative air pressure results in air being removedfrom the space between the squeegee blades and in front of the leadingsqueegee blade 126A. Together with the air, the cleaning liquid on thefloor surface, along with the dirt that is now in suspension, is alsocollected.

Squeegee assembly 120 is located relatively close to scrubber brush 80.Preferably the distance between the point of contact of scrubber brush80 with the floor and the point of contact of the leading squeegee blade126A with the floor is less than about 5 inches. Placing the squeegeeassembly 120 relatively close to scrubber brush 80 results in at leasttwo advantages. First, it results in making cleaner 10 more compact soas to enable mounting all of the components necessary for performingthree cleaning operations on a single cleaning apparatus. Second, itallows squeegee assembly 120 to remove the cleaning liquid deposited byscrubber brush 80 shortly after it is deposited, thereby reducing thepossibility of trails of cleaning liquid being left behind.

Vacuum and Liquid Subsystem

Referring to FIGS. 14, 14A, and 15-16, vacuum and liquid subsystem 30includes a liquid recovery tank 190, a filter 192, a vacuum motor 194,and a fluid pump 196. A hose (not shown) connects liquid recovery tank190 to pipe 136 of plenum 134. At liquid recovery tank 190, the hoseconnects to an end 198A of a pipe 198. Pipe 198 at another end 198Bopens into the cavity of liquid recovery tank 190, near the top ofliquid recovery tank 190. Liquid recovery tank 190 is filled such thatthe cleaning liquid level always remains below opening 198B of pipe 198.The cleaning liquid may be water or other cleaning liquids commonly usedfor scrubbing floors.

Vacuum motor 194 is connected to liquid recovery tank 190 through an airinlet 200. Air inlet 200 is capped by a wire mesh strain 202 whichprevents foreign objects, such as hair, from reaching vacuum motor 194.Air inlet 200 and strain 202 are located inside a removable clearplastic dome 204. Plastic dome 204 allows the user to inspect strain 202visually so as to remove any dirt collected by strain 202, if necessary.

Fluid pump 196 is connected to trough 112 (shown in FIG. 11) through ahose 206. Fluid pump 196 is connected to liquid recovery tank 190through filter 192. A fluid valve 196A is located between fluid pump 196and filter 192. Some embodiments do not include a fluid valve. Fluidpump 196 and fluid valve 196A are connected to a dedicated drivercontrolled by control subsystem 34, as will be described in furtherdetail below.

As vacuum pump 194 operates, a negative pressure is created in liquidrecovery tank 190 resulting in a suction being applied to pipe 198, andhence to plenum 134 and the space between squeegee blades 126A-B. Thesuction creates a flow of an air and now dirty cleaning liquid mixturecollected from the space between squeegee blades 126A-B and the area infront of the leading squeegee blade 126A. As the flow of air andcleaning liquid mixture enters liquid recovery tank 190, the speed ofthe flow suddenly decreases since the volume in which the mixture canflow suddenly increases. The sudden decrease in the speed of the flowresults in the liquid separating from the air and falling into the tank.Fluid pump 196 pumps the cleaning liquid in recovery tank 190 throughfilter 192 which removes the dirt particles in the cleaning liquid.

Burnisher Assembly

Referring to FIGS. 17, 18 and 19, burnisher assembly 16 includes aburnisher pad 160, a burnisher pad cover 162, a motor 168 and aburnisher linkage assembly 170. Burnisher pad 160 is made out of porous,non-woven, air-layered fibrous material secured together with anadhesive binder. Preferably, burnisher pad 160 has characteristicspreviously proven suitable for use with commercial UHS finishes.Burnisher pad 160 is directly connected a DC servo motor 168 controlledby the control subsystem 34. Motor 168 can spin burnisher pad at speedsof up to about 3500 and preferably up to about 2800 rpm, and preferablyat about or above 2100 rpm.

Burnisher pad cover 162 is characterized by a semicircular groove 164which has a gradually rising profile. During operation, as motor 168spins burnisher pad 160, burnisher pad 160 creates a spinning air flowwhich moves upward and carries dust particles from the floor surfacewith it. Groove 164 directs this air flow toward exit opening 166 andinto a pipe (not shown) which is connected to a porous vacuum cleanerfilter bag (not shown). The vacuum cleaner bag collects the dust butallows the air to flow out of the bag.

Linkage assembly 170 is a spring loaded four bar linkage. Linkageassembly 170 includes a burnisher support member 172 and a mountingframe 174 for connecting burnisher assembly 16 to frame 18 of cleaner 10(shown in FIGS. 1-2). Linkage assembly 170 includes four horizontallinkage bars 176, each of which is connected at one end to burnishersupport member 172 and at another end to mounting frame 174. A pair ofcoil springs 178A are located at the mounting frame end of linkage bars176. Another pair of coil springs 178B are located at the support memberend of linkage bars 176. Coil springs 178A-B are mounted to resist thedownward force exerted by the weight of burnisher pad 160, burnisher padcover 162, and motor 168, and to allow burnisher pad 160 to float nearthe floor surface.

To lift and lower burnisher pad 160, burnisher assembly 16 includes amotor 182 connected to a cam 180. Cam 180 engages an extended portion184 of support member 172. Motor 182 is connected to a DC servo motordriver controlled by control subsystem 34, as will be described infurther detail below. As motor 182 rotates cam 180, burnisher pad 160 iseither lifted or lowered. Note that the movement of burnisher pad 160 issubstantially vertical. This substantially vertical movement reduces theextent to which burnisher pad 160 needs to be lifted so that all pointsof burnisher pad 160 have a predetermined clearance from the floor.Hence, the amount of space required for accommodating burnisher assembly16 in its retracted position is less than otherwise may be the case,thereby making it possible to have components for performing threecleaning operations on the same cleaning apparatus.

We have observed that having burnisher assembly 16 and scrubber assembly14 on the same frame results in significantly improved cleaning results.The present system provides the advantage of performing multipleoperations with a single pass of cleaner 10 over the floor. We havediscovered that combining the burnishing operation with one or more ofthe sweeping and/or scrubbing operations, particularly the scrubbingoperation, in a unitary, coordinated system so that the operations areperformed serially provides certain advantages not previously achievedor recognized.

In particular, embodiments of cleaner 10 clean waxed floors withsignificantly better luster and shine than when the same cleaningoperations are performed separately, in more than one pass, at widelyspaced intervals as are typically performed by an operator usingseparate devices. We currently hypothesize that the improved results maybe because the scrubbing and burnishing operations are performed closelyspaced in time. In other words, it may be that the burnishing operationprovides enhanced results when it is performed within a short time afterthe scrubbing operation resulting in increased gloss.

If that is the case, a cleaner, comprising a connected “train” ofdevices coordinated mechanically or electronically to perform thecleaning operations in the desired order and in close proximity in time,may achieve similar results.

We also currently hypothesize that the improved performance may bebecause scrubber assembly 14 when scrubbing the floor softens the wax orrenders it plastic-like. Because burnisher assembly 16 starts burnishingshortly afterward, the wax is still in its softened or plastic state.Hence, the results of burnishing is significantly improved.

If that is the case, it may be possible to get the same advantage inother manner, so long as the wax remains in a softened or plastic statewhen the floor is burnished. For example, it is possible to usechemicals which reduce the rate of hardening of the wax after thescrubbing, resulting in the wax remaining in its plastic/softened state.Or, it may be possible to place a chemical on the floor or heat thefloor to soften the wax or render it plastic-like just before burnishingthe floor.

Control Subsystem

Control subsystem 34 receives inputs from tile user, and, based on thoseinputs, operates cleaner 10. Control subsystem 34 also coordinates amongvarious operations performed by cleaner 10. We will first describe thecircuitry of control subsystem 34. We will then describe the applicationprograms executed by subsystem 34.

FIG. 20 is a schematic diagram of the circuitry of control subsystem 34.Control subsystem 34 receives input signals from pressure sensing pads26A-B and the controls on control panel 22 (shown in FIG. 1). Thesesignals are received by a user interface board 1014. The signalsassociated with the emergency stop button and key switch are in additionreceived by a power distribution system 1008.

Power distribution system 1008 includes DC-DC converters that convertthe voltage supply from batteries 32 (e.g., 36 or 48V) to variousvoltages required by various components of cleaner 10. Powerdistribution system 1008 also includes circuitry for performing astart-up sequence. During the start-up sequence, power distributionsystem 1008 measures the battery voltage and determines whether correctvoltages are output by its the DC-DC converters. If correct voltages areoutput, power distribution system 1008 will turn on the rest of thecomponents of control subsystem 34.

Power distribution system 1008 also implements a number of safetyfeatures. For example, in response to an input from the emergency stopbutton on control panel 22, power distribution system 1008 immediatelycuts off all power to all components. Power distribution system 1008also does not allow cleaner 10 to operate when housing 20 is notproperly attached to frame 18 (FIG. 1).

A Power monitoring board 1010 monitors the overall power consumption ofcleaner 10, and power consumption of each subsystem.

User interface board 1014, in response to signals from control panel 22and pressure sensing pads 26A-B, generates commands to be transmitted toother components of control subsystem 34 through a neuron interface card1018 connected to a system bus 1026. User interface board 1014 alsosends signals to control panel 22 for lighting appropriate status LEDsto indicate to the user that various requested operations are beingperformed.

Control subsystem 34 includes a main processor board 1024 which includesa microprocessor for executing various application programs foroperating cleaner 10. In the described embodiment, the microprocessor onprocessor board 1024 is an MC68332 processor manufactured by MotorolaCorporation. Processor board 1024 is connected to system bus 1026through a neuron interface board 1016. Processor board 1024 alsoincludes a memory for storing the application programs executed thereon.

Processor board 1024 is also connected to a two-axis motor controllerboard 1028 which controls the operation of drive wheel motors 64.Two-axis motor controller board 1028 receives velocity control commandswith respect to drive wheel motors 64 from processor board 1024.Two-axis motor controller board 1028 translates the velocity controlcommands to appropriate DC analog signals for driving universal motordriver boards 1030-1032, each of which is respectively connected to oneof drive wheel motors 64. Universal motor driver boards 1030-1032amplify the received signals and directly drive motors 64.

The speed of each one of drive wheels 28A-B is monitored and controlledby a closed loop velocity control system implemented by encoders1034-1036, two-axis motor controller board 1028, and the applicationprograms running on processor board 1024. Generally, encoders 1034-1036send signals corresponding to the speed of rotation of each one of drivewheels 28A-B to two-axis motor controller board 1028. Encoders 1034-1036can be optical or magnetic encoders. Two-axis motor controller board1028 translates the signals from encoders 1034-1036 to appropriate datatransmitted to processor board 1024. The application programs running onprocessor board 1024 use the data to ensure that drive wheels 28A-B arerotating at correct speeds by adjusting the speed commands sent totwo-axis motor controller board 1028, as will be described in detailbelow.

The circuitry of control subsystem 34 also includes a cleaning actuatorboard 1038 which receives instructions from application programs runningon processor board 1024 through a neuron interface card 1022. Cleaningactuator board 1038 includes a microprocessor and a memory. The memorystores application programs which in response to the commands fromprocessor board 1024 operate the various drivers and motors connected tocleaning actuator board 1038. Each one of the motors connected tocleaning actuator board 1038 is driven by a dedicated driver. Driversfor scrubber motor 86, vacuum pump 194, and burnisher motor 168 are notpart of cleaning actuator board 1038. All other motor drivers(designated as ‘MD’) are part of cleaning actuator board 1038.

A plurality of limit switches 1046 are positioned appropriately oncleaner 10, and are connected to cleaning actuator board 1038. Each oneof limit switches 1046 provides a signal to cleaning actuator board 1038when a moving component to which that limit switch connected reaches apredetermined position. For example, two limit switches are provided forsweeper assembly 12. One of those limit switches provides a signal tocleaning actuator board 1038 when sweeper assembly 12 reaches itslowered position. Another one of these limit switches provides a signalwhen sweeper assembly 12 reaches its retracted position. Similarly,three limit switches are provided for burnisher assembly 16 to provideindication of when burnisher assembly 16 reaches any one of its threepositions. Other limit switches provide signals regarding the twopositions of scrubber brush 80, the two positions of squeegee assembly120, and the two positions of splash and drip guard 96. In addition tolimit switches 1046, a set of status switches 1048 provide informationwith respect to whether liquid recovery tank 190 (shown in FIG. 15) isfull or empty, and whether hopper 42 (shown in FIG. 5) is missing or isfull.

Having described the circuitry of control subsystem 34, we will nowdescribe the application programs running on processor board 1024 andcleaning actuator board 1038. These application programs generally havea behavior based architecture. Programs having behavior basedarchitecture are typically used for robotics applications where a robotis conceptualized as having a number of interdependent behaviors, thatis, behaviors which are in part independent of one another and in partdependent on one another. Typically, such programs are designed to havemultiple behavior modules, where each one of the behavior modules isresponsible for implementing one of the behaviors of the robot. Allbehavior modules typically run in parallel to one another on a sameprocessor, or on different processors. Each behavior module can bethought of as a set of instructions that can be activated or deactivatedbased on outputs by other behavior modules or based on environmentalconditions. Typically, there is more than one way for a behavior moduleto be activated or deactivated, and the behavior module can actdifferently depending on how it is activated or deactivated. For anoverview of behavior based programming see R. A. Brooks, “The BehaviorLanguage; User's Guide” A.I. Memo 1227, Massachusetts Institute ofTechnology—Artificial Intelligence Laboratory, 1990.

We have found behavior based programming particularly suitable forcleaner 10. Cleaner 10 has various subsystems, each of which performs aparticular cleaning function. The operation of each of these subsystemsneeds to be controlled partly independent of the operation of othersubsystems and partly dependent on the operation of the othersubsystems. In addition, the operation of each of the subsystems must beoptimized in part independently of the other subsystems and in partbased on the operations of the other subsystem.

To understand this, consider the following subsystems of cleaner 10:scrubber assembly 14, burnisher assembly 16, and drive wheels 2SA-B.These subsystems operate substantially independent of one another.However, in some respects, their operations depend on one another. Forexample, the speed at which burnisher pad 160 is spun depends on thespeed at which cleaner 10 is driven. In addition, burnisher pad 160should be preferably placed onto a particular area of the floor onlyafter cleaner 10 has scrubbed that area. This minimizes damage to thefloor. In the described embodiment, to ensure that burnisher pad 160 isplaced over an already scrubbed area, burnisher pad 160 is lowered onlyafter cleaner 10 has traveled a sufficient distance to ensure thatburnisher pad 160 is over an area scrubbed by scrubber assembly 14.Moreover, to improve cleaning quality, after the operator has decided tostop scrubbing the floor, cleaner 10 should travel a sufficient distanceso that squeegee assembly 120 removes cleaning liquid deposited byscrubber brush 80.

As already stated, behavior based programming allows having multiplebehavior modules running in parallel enabling controlling and optimizingvarious subsystems independently of one another. At the same time, suchprogramming allows coordination of the operation of various subsystemsbased on one another. In control subsystem 34, there are two levels ofbehavior modules. One set of behavior modules are high level behaviormodules which are executed by processor board 1024. These behaviormodules implement high level behaviors of cleaner 10 such as driving,sweeping, scrubbing, and burnishing. A second set of behavior modulesare low level behavior modules which are executed by cleaning actuatorboard 1038. These behavior modules implement low level behaviors ofcleaner 10 controlling operations of all of the motors on cleaner 10,except for drive wheel motors 64.

The high level behavior modules depend on independent and properexecution of the low level behavior modules. The high level behaviormodules issue commands to the low level behavior modules. The low-levelbehavior modules then implement a sequence of steps to implement theparticular, requested behavior. The high level behavior modules, afterissuing commands, do not monitor the operation of the low level behaviormodules and proceed to execute other steps. After receiving a command,the low level behavior modules do not require any further input from thehigh level behavior modules. In essence, the commands are implementedaccording to a “fire and forget” architecture: after issuing a command,the high level behavior modules can forget about the low level behaviorand assume that it will be implemented. This architecture allows thehigh level behavior modules to be optimized for implementing the highlevel behaviors rather than for implementing the low level behaviors.This architecture also allows optimizing the low level behaviors solelyfor implementing the low level behaviors without any concern about thehigh level behaviors.

The low level behavior modules can be categorized and described based onthe type of motors they operate. There are generally two types of motorsin cleaner 10. The first type of motors operate the various componentsperforming cleaning operations. These motors are sweeper brush motors38A-B, scrubber brush motor 86, vacuum pump 194, fluid pump motor 196,and burnisher motor 168. The low level behavior modules controlling theoperation of the first type of motors receive commands indicating that amotor should either start or stop operating. These lower level behaviormodules translate those commands to instructions required by thecorresponding drivers.

The second type of motors in cleaner 10 retract and lower variouscomponents of cleaner 10. These motors include sweeper lift motor 58,scrubber lift motor 106, splash and drip guard motor 104, squeegee liftmotor 150, and burnisher lift motor 182. Each one of the low levelbehavior modules controlling the operations of these motors, afterreceiving a command, provide commands to a corresponding driver to startthe appropriate motor. The behavior module then monitors signals fromcorresponding limit switches to determine when the component has reachedthe desired position and then sends commands to stop the motor.

We will now describe the high level behavior modules in reference toFIGS. 21-30. FIG. 21, shows a behavior diagram of the high levelbehavior modules running on processor board 1024. There are nineseparate behavior modules which run in parallel on processor board 1024.FIGS. 22-30 are pseudo codes for the steps taken by these nine behaviormodules.

These nine behavior modules can be divided into three groups. The firstgroup of behavior modules implement three user interface and errorbehaviors: control behavior module 2100, handles behavior module 2200,and error behavior module 2900. The second group of behavior modulesimplement two coordinating behaviors: enable behavior module 2400 anddistance behavior module 2800. The third group of behavior modulesimplement four operational behaviors: sweep behavior module 2500, scrubbehavior module 2600, drive behavior module 2700, and burnish behaviormodule 2800.

Referring to FIG. 22, error behavior module 2900 sets an ERROR flag whenstatus switches 1048 indicate that hopper 42 is either missing, orliquid recovery tank 190 is either overflowing or empty. Error behaviormodule 2900 also sets the ERROR flag when there is a system errorcomprising an electronic detection of a mechanical problem (step 2902).The ERROR flag causes other behavior modules to stop all operations oncleaner 10.

Referring to FIG. 23, control behavior module 2100 translates datacorresponding to signals from control panel 22 to output commandscorresponding to the user's selections. These outputs include commandsfor commencing or stopping any one of the cleaning operations and aparticular speed selected by the user.

Referring to FIG. 24, handles behavior module 2200 first determineswhether the ERROR flag is set (step 2202). If so, handles behaviormodule 2200 sets RIGHT-HANDLE and LEFT-HANDLE variables to valuescorresponding to signals from left and right pressure sensing pads 26A-B(steps 2204). If either one of the RIGHT-HANDLE and LEFT-HANDLEvariables is set, handles behavior module 2200 measures and outputs aTIME-ENABLED variable which measures the period since when one or bothpressure sensing pads 26A-B have been pressed (step 2206). If neitherone of pressure sensing pads 26A-B is pressed, handles behavior module2200 outputs a TIME-DISABLED variable which measures the continuousperiod of time when neither one of the pressure sensing pads 26A-B hasbeen pressed (steps 2208). Additionally, if either one of left and rightpressure sensing pads 26A-B is pressed, handles behavior module 2200sets an ENABLED flag (step 2210).

If the ERROR flag is set (step 2202), handles behavior module 2200 setsthe ENABLED, RIGHT-HANDLED, LEFT-HANDLED, TIME-ENABLED, andTIME-DISABLED variables to false (steps 2212).

Referring to FIG. 25, enable behavior module 2400 implements acoordinating behavior and is responsible for setting a DRIVE-ENABLEDflag which determines whether drive wheel motors 64 can operate drivewheels 28A-B. Enable behavior module 2400 sets the DRIVE-ENABLED flagwhen three conditions are met. First, the ENABLED flag must be set byhandles behavior module 2200. Second, sweeper brushes 36A-B must beeither in their retracted or lowered positions. Third, scrubber brush 80must be either in its retracted or lowered position. When all threeconditions are met, enable behavior module 2400 sets the DRIVE-ENABLEDflag. Enable behavior module 2400 thereby prevents movement of cleaner10 when pressure sensing pads 26A-B are not being pressed, sweeperbrushes 36A-B are in the process of being retracted or lowered, orscrubber brush 80 is in the process of being retracted or lowered.

Referring to FIG. 26, sweep behavior module 2500 implements the sweepingbehavior of cleaner 10. If the SWEEP-CMD flag is set, the SPEED variableis not set for reverse speed, and the ERROR flag is not set (step 2502),sweep behavior module 2500 provides commands to turn on sweeper brushmotors 38A-B and to lower sweeper brushes 36A-B (steps 2504). Sweepcommand behavior module 2500 starts sweeper brush motors 38A-B onlyafter the value of the TIME-ENABLED variable is greater than apredetermined DELAY-ON-SWEEP-START constant. Similarly, sweep commandbehavior module 2500 sends the command for lowering sweeper brushes36A-B only after the TIME-ENABLED variable is greater than apredetermined DELAY-ON-SWEEP-LOWER constant. These delays ensure thatsweeping does not begin until after the operator has applied pressure topressure sensing pads 26A-B for a predetermined period of time. Sweepcommand behavior module 2500 also sets a SWEEPING flag indicating thatthe cleaner 10 has begun sweeping the floor (steps 2506).

If the TIME-DISABLED variable is greater than a DELAY-OFF-SWEEP-RAISEconstant, indicating that the user has removed his hands from pressuresensing pads 26A-B for more than a predetermined period of time, sweepbehavior module 2500 stops sweeping operation by first raising sweepingbrushes 36A-B (steps 2508). After a further delay determined by aDELAY-OFF-SWEEP-STOP constant, sweep behavior module 2500 stops sweepingbrush motors 38A-B (steps 2510). These delays ensure that cleaner 10continues to sweep, even when the operator removes his hands from thepressure sensing pads 26A-B momentarily. At the same time, stopping thesweeping (and other operations, as will be described below) ensures thatcleaner 10 does not operate unless there is an operator present. This isan important “time out” safety feature of cleaner 10.

If the SWEEP-CMD flag is not set, the SPEED variable is set for reversespeed, or the ERROR flag is set (step 2502), then sweep behavior module2500 stops cleaner 10 from sweeping immediately and sets the SWEEPINGflag to false (steps 2512).

Referring to FIG. 27, scrub behavior module 2600 implements scrubbingbehavior of cleaner 10. If the SCRUB-CMD flag is set, the SPEED variableis not set for reverse, and the ERROR flag is not set, then scrubbehavior module 2600 determines whether the TIME-ENABLED variable isgreater than a predetermined DELAY-ON-SCRUB-START constant indicatingthat the user has applied pressure to pressure sensing pads 26A-B for asufficiently long time for cleaner 10 to start scrubbing (step 2602). Ifso, scrub behavior module 2600 issues commands for retracting splash anddrip guard 96, starting scrubber brush motor 86, starting vacuum pump194, lowering squeegee assembly 120, and opening fluid valve 196A (steps2604). If scrub behavior module 2600 determines that the TIME-ENABLEvariable is greater than a further DELAY-ON-SCRUBBER-LOWER constant,scrub behavior module 2600 starts fluid pump 196, lowers scrubber brush80, and sets a SCRUBBING flag to indicate that cleaner 10 is scrubbingthe floor (steps 2606).

If scrub behavior module 2600 determines that the TIME-DISABLE variableis greater than a predetermined DELAY-OFF-SCRUBBER-RAISE constant,indicating that the user has stopped applying pressure to pressuresensing pads 26A-B, scrub behavior module 2600 stops cleaner 10 fromscrubbing (steps 2608). To do so, scrub behavior module 2600 firstdetermines whether the TIME-DISABLED variable is greater than aDELAY-OFF-SCRUBBER-RAISE constant. If so, scrubber brush 80 is lifted,the SCRUBBING flag is set to false, and fluid pump 196 is shut off. Ifscrub behavior module 2600 then determines that the TIME-DISABLEDvariable is greater than a predetermined DELAY-OFF-SCRUBBER-STOPconstant, scrub behavior module 2600 shuts off scrubber brush motor 86,and closes fluid valve 196A (steps 2610). Scrub behavior module 2600then proceeds to lower splash and drip guard 96, raise squeegee assembly120, and turn off vacuum pump 194, but only after determining that aSQUEEGEE-SAFE flag is set. The SQUEEGEE-SAFE flag indicates whethersqueegee blades 126A-B have traveled a sufficient distance to remove thecleaning liquid deposited by scrubber brush 80 before it was lifted(steps 2612). The SQUEEGEE-SAFE flag is set by distance behavior module2800, as will be described below.

If the SCRUB-CMD flag is not set, the SPEED variable is set to reverse,or the ERROR flag is set, scrub behavior module 2600 stops cleaner 10from scrubbing without any delay. To do so, scrub behavior module 2600sends commands to raise scrubber brush 80, set the SCRUBBING flag tofalse, shut off fluid pump 196, turn off scrubber brush motor 86, andclose fluid valve 196A (steps 2614). If the SPEED variable is set toreverse or the ERROR flag is set, scrub behavior module 2600 also sendscommands to lower splash and drip guard 96, raise squeegee assembly 120,and turn off vacuum pump 194 (steps 2616). Other vise, these steps aretaken only after the SQUEEGEE-SAFE flag is set indicating that squeegeeassembly 120 has traveled over an area cleaned by scrubber brush 80 andhence has removed the cleaning liquid deposited by scrubber brush 80 onthe floor.

Referring to FIG. 28, drive behavior module 2700 implements the drivingbehavior of cleaner 10 by controlling the operation of drive wheels28A-B of cleaner 10. To do so, drive behavior module 2700 implements twofunctions. First, drive behavior module 2700 monitors and adjusts thespeed of drive wheels 28A-B to ensure that they track a speed selectedby the user. Second, drive behavior module 2700 controls the directionof travel of cleaner 10.

To implement the first function, drive behavior module 2700 compares thecurrent speed of each one of drive wheels 28A-B to the speed selected bythe user. As discussed above, the current speed is measured by encoders1034-1036 (shown in FIG. 20). If the current speed of either one ofdrive wheels 28A-B is not the same as the speed selected by the user,drive behavior module 2700 adjusts the speed of that drive wheel to moreclosely track the selected speed (steps 2702). As mentioned above, inthis manner, a closed-loop velocity control of drive wheels 28A-B isimplemented in cleaner 10.

To implement the second function, drive behavior module 2700 controlsthe speed of drive wheels 28A-B individually to move cleaner 10 forwardand backward, turn cleaner 10 to the left or right, and stop cleaner 10.To implement a left turn, drive behavior module 2700 stops left drivewheel 28B from rotating and allows right drive wheel 28A to continue torotate. To implement a right turn, drive behavior module 2700 stopsright drive wheel 28B from rotating and allows left drive wheel 28A tocontinue to rotate. To stop cleaner 10, drive behavior module 2700 stopsboth drive wheels 28A-B. To move cleaner 10 forward or in reverse in astraight line, drive behavior module 2700 rotates both drive wheels28A-B at the same speed and in the same direction.

We will now describe the specific manner in which drive behavior module2700 implements the above method of directional control. First, drivebehavior module 2700 determines whether the DRIVE-ENABLED flag is setand the ERROR flag is not set (step 2704). Then, if the user is pressingleft pressure sensing pad 26B, drive behavior module 2700 sets speed ofright drive wheel 28A to the speed selected by the user (steps 2706). Ifthe user is not pressing left pressure sensing pad 26B, drive behaviormodule 2700 sets speed of right drive wheel 28A to zero causing theright drive wheel to stop (steps 2708). In a similar fashion, if theuser is pressing right pressure sensing pad 26A, drive behavior module2700 sets speed of left drive wheel 28B to the speed selected by theuser (steps 2710). If the user is not pressing right pressure sensingpad 26B, drive behavior module 2700 sets speed of left drive wheel 28Bto zero causing the left drive wheel to stop (steps 2712). If either oneof the left and right pressure sensing pads 26A-B is being pressed,drive behavior module 2700 sets the DRIVING flag to true (steps 2714).If neither one of the pressure sensing pads 26A-B is being pressed,drive behavior module 2700 sets the DRIVING flag to false (steps 2716).In this case, drive behavior module 2700 also sets the speed of bothwheels to zero, thereby stopping cleaner 10 (steps 2718).

Referring to FIG. 29, distance behavior module 2800 implements acoordinating behavior for coordinating among scrub behavior module 2600,drive behavior module 2700, and burnish behavior module 2900. Generally,distance behavior module 2800 ensures that burnishing does not beginuntil cleaner 10 has traveled a sufficient distance to be located overan area already scrubbed by scrubber assembly 12. Distance behaviormodule 2800 also ensures that squeegee blades 126A-B are not lifted fromthe floor until cleaner 10 has traveled a sufficient distance forsqueegee assembly 120 to remove the cleaning liquid deposited byscrubber brush 80. To implement these functions, drive behavior module2800 supplies flags to scrub behavior module 2600 and burnish behaviormodule 2900 to either prevent from performing their particular cleaningoperations, or allow them to perform their cleaning operations.

Distance behavior module 2800 first determines whether scrubber assembly12 is scrubbing (step 2802). If so, distance behavior module 2800calculates the distance traveled by cleaner 10 based on the actualspeeds of the left and right drive wheels 28A-B determined by readingsfrom encoders 1034-1036, and rate of velocity updates (steps 2804). Inalternative embodiments, the distance can be estimated by apredetermined time constant, or by the speed selected by the user ratherthan the actual speed. If Distance behavior module 2800 determines thatthe SCRUBBING flag is false, indicating that scrubber assembly 12 is notcurrently scrubbing, distance behavior module 2800 sets aBURNISH-DISTANCE variable to false, thereby preventing burnish behaviormodule 2800 from starting the burnishing.

If distance behavior module 2800 determines that the SCRUBBING flag isset, then distance behavior module 2800 sets SQUEEGEE-DISTANCE andSQUEEGEE-TIME variables to false (steps 2806).

If Distance behavior module 2800 determines that the SCRUBBING flag isnot set and the SQUEEGEE-DISTANCE variable is false, indicating thatscrubber assembly just finished scrubbing, then Distance behavior module2800 sets the SQUEEGEE-DISTANCE variable to zero (steps 2808). TheSQUEEGEE-DISTANCE variable indicates the distance cleaner 10 travelsfrom the time scrubber assembly 12 stops scrubbing. Distance behaviormodule 2800 also sets the SQUEEGEE-TIME variable to the appropriate timewhen squeegee blades 126A-B must be lifted off the floor, if not alreadylifted (step 2810).

If the SCRUBBING flag is not set and the SQUEEGEE-DISTANCE variable isnot false, distance behavior module 2800 determines that scrubberassembly 12 has finished scrubbing and distance behavior module 2800 isin the process of measuring the distance traveled by cleaner 10 sincescrubbing stopped. Hence, distance behavior module 2800 calculates thedistance based on the actual speeds of left and right drive wheels 28A-Bdetermined by readings from encoders 1034-1036, and rate of velocityupdate (steps 2812). Distance behavior module 2800 then determineswhether the SQUEEGEE-TIME variable has been set, indicating thatscrubber assembly 12 has finished scrubbing (step 2814). If so, distancebehavior module 2800 determines whether cleaner 10 has traveled asufficient distance or whether sufficient time has passed, so thatsqueegee blade 126A-B should be lifted anyway (steps 2816). Distancebehavior module 2800 then sets the SQUEEGEE-SAFE flag accordingly (steps2818). As described above, SQUEEGEE-SAFE flag is used by scrub behaviormodule 2700 to determine whether to lift squeegee blades 126A-B.

Next, distance behavior module 2800 determines whether cleaner 10 hastraveled sufficient distance for burnisher assembly 16 to beginburnishing (step 2820). Distance behavior module 2800 sets aBURNISH-SAFE flag accordingly (steps 2822).

Referring to FIG. 30, burnish behavior module 2900 implements burnishingbehavior of cleaner 10. If a BURNISH-CMD flag is set, the SPEED variableis not set for reverse, and the ERROR nag is not set (steps 2902), thenburnish behavior module 2900 determines whether the TIME-ENABLEDvariable is greater than a predetermined DELAY-ON-BURNISH-STARTconstant. If the TIME-ENABLED variable is greater that theDELAY-ON-BURNISH-START constant, burnish behavior module 2900 determinesthat the user has applied pressure to pressure sensing pads 26A-B for asufficiently long time for cleaner 10 to start burnishing. Burnishbehavior module 2900 then issues a command to start burnisher motor 168(steps 2902). Note that burnisher motor 168 spins at different speeds,depending on the speed of cleaner 10 selected by the user. If theBURNISH-SAFE flag and the DRIVING flag are set, burnish behavior module2900 sends a command for lowering burnisher pad 160 to the floor andsets a BURNISHING flag (steps 2906). Otherwise, burnish behavior module2900 retracts burnisher pad 160 to its intermediate position (steps2908).

If burnish behavior module 2900 determines that the TIME-DISABLEvariable is greater than a predetermined DELAY-OFF-BURNISHER-STOPconstant, indicating that the user has stopped applying pressure topressure sensing pads 26A-B, burnish behavior module 2900 stops cleaner10 from burnishing (steps 2910). To do so, burnish behavior module 2900sends a command to retract burnisher pad 160 to its intermediateposition, sets the BURNISHING flag to false, and turns off burnishermotor 168 (steps 2910).

If burnish behavior module 2900 determines that the TIME-DISABLEvariable is greater than a predetermined DELAY-OFF-BURNISHER-RAISEconstant, burnish behavior module 2900 sends a command to retractburnisher pad 160 completely (steps 2914).

If BURNISH-CMD is not set, the SPEED variable is set to reverse, or theERROR flag is set, then burnish behavior nodule 2900 stops cleaner 10from burnishing immediately without delay. To do so, burnish behaviormodule 2900 retracts burnisher pad 160 completely, sets BURNISHING flagto false, and turns off burnisher motor 168.

In this way, the operation of cleaner 10, FIG. 1 and each of the primarycomponents thereof, namely drive wheels 28A-B, FIG. 2; sweeper assembly12; scrubber assembly 14 including vacuum 194, FIG. 15; squeegeeassembly 126A-B, FIG. 7, and fluid pump 196, FIG. 15; and burnisherassembly 16, FIG. 1 is greatly simplified by the implementation andarchitecture of control system 34, FIG. 20.

Without such a control system, the user, to begin cleaning a floor,would be required, inter alia, to engage drivewheels 28A-B, FIG. 2,lower sweeper assembly 12, engage sweeper motors 38A-B, lower scrubberassembly 14 and squeegee assembly 12, engage scrubber motor 86, FIG. 8,turn on vacuum pump 194, FIG. 15 and fluid pump 196, and then lowerburnisher assembly 16, FIG. 2 and activate burnisher motor 168, FIG. 17to rotate burnisher pad 160.

Each time the cleaner is stopped, the user would then be required toreverse this process.

As such, although cleaner 10 uniquely includes three cleaning heads,control system 34 or its equivalent is highly desirable: otherwise theoperational requirements of cleaner 10 would be overly complex.

In this invention, control system 34 renders the operation of cleaner 10nearly autonomous to the extent that cleaning is effected by the userissuing only two commands and, conversely, the cleaning apparatusautomatically ceasing to operate, when the user issues only one command,without damaging the floor and without leaving cleaning fluid on thefloor.

In operation, the user typically enters a cleaning mode command viacontrol panel 22 and touches one or both of pressure sensing pads 26A-B,FIG. 1.

Control system 34, FIG. 20 then automatically signals drive motor 64,FIG. 2 to turn drivewheels 28A-B, signals motors 38A-B to turn sweeperbrushes 36A-B, provides signals to sweeper assembly 12 motor 58, FIG. 5which lowers hopper 42 and sweeper brushes 36A-B, signals scrubber brush80 motor 86, FIG. 14 which, in response, spins scrubber brush 80,provides signals to motor 106 to lower scrubber brush 80 and squeegeeassembly 126A-B, signals motor 104, FIG. 10 to rotate splash guard 96,FIG. 9A, provides signals to vacuum pump 194, FIG. 15 and fluid pump 196to turn them on, signals burnisher motor 168, FIG. 17 to rotateburnisher pad 160, and finally, signals burnisher assembly 16 motor 182to lower burnisher assembly 16, FIG. 2.

Preferably, control system 34, FIG. 20 performs these operationsautomatically in the sequence listed above but this particular sequenceis not a limitation of the present invention. Indeed, once the drivewheels begin to turn, all of the cleaning heads may begin to rotate andall of the cleaning assemblies lowered at the same time as the vacuumpump and the fluid pump are energized.

When the operator removes his hands from both sensing pads 26A-B, FIG.1, enters any mode command other than the cleaning mode command, and/orif an error flag is detected, control system 34 essentially reverses thesequence of operations listed above except that, in the preferredembodiment, signals are first provided to turn fluid pump 196 off beforevacuum pump 194 is turned off, before squeegee assembly 120 is raised,before burnisher assembly 16, scrubber assembly 14, and sweeper assembly12 are raised, and before the operation of burnisher pad 160, scrubberbrush 80, and sweeper brushes 36A-B stops.

Typically, at least vacuum pump 194 remains on and squeegee assembly 120lowered for the deceleration period of cleaner 10.

In this way, control system 34 greatly simplifies the operation ofcleaner 10 and, at the same time, insures that the floor is not damagedand/or that cleaning fluid is not left on the floor.

Although control system 34 is described above with respect to a cleanerwith three cleaning heads, control system 34 could be modifiedaccordingly and implemented in a cleaner with only a scrubbing brush orpad and a burnishing pad or pads. Moreover, although a behavior basedarchitecture is described, control system 34 could be implemented usingdifferent software algorithms or even electronic circuitry withoutprocessors. Accordingly, control system 34 and its associated circuitrycould be implemented based on microprocessor software algorithmsincluding but not limited to behavior based architectures or based onanalog or digital circuitry architectures.

While not intending to be bound by any particular explanation for thephenomena resulting from the practice of the present invention, it isbelieved that a combination of factors may be contributing to thesurprising results achieved by the present invention. It is known thatsome polymeric coatings are hydrophilic in character and tend to absorbsome water on contact. Typically the repair of the surface of thecoating involves primarily a thin region near the surface of thecoating. Performing the burnishing closely in time after the scrubbingmay permit the burnishing to occur while the surface region of thepolymeric coating contains some absorbed wash water. At this time, thesurface of the coating may be temporarily in a softened, malleableplastic state as a result of absorption of a portion of the washingliquid. This effect may be enhanced with particularly hydrophiliccoatings or by the use of surfactants or other additives added to thewashing liquid. The liquid begins to evaporate into the air from thisthin surface zone quickly after the bulk liquid is removed form thesurface so that in conventional practice the burnishing operation isperformed after the coating has already dried and hardened. In the drystate, the coating is more frangible or friable and is subject tocreation of scratches. However, while the coating contains a substantialamount of the additional, absorbed liquid it may temporarily be in asofter and more malleable state and is more likely to flow and bedeformed or displaced rather than scratched or broken. This may resultin a smoother surface being created by the burnishing operation. Thus,it is a feature of the method and device of the present invention thatthe burnishing take place while the coating contains a significantamount of additional water and before it has transitioned back to thehard, dry state. A squeegee, vacuum or other mechanism is locatedfollowing the scrubber to remove bulk water from the surface of thefloor after scrubbing and before burnishing. Because the coating beginsto dry after the bulk water is removed from the surface, it is desirablethat the burnisher be placed as close as practical after the point wherethe bulk surface water is removed. Also, it is preferred that the bulkliquid removal point be located so that the water will have sufficienttime to penetrate the coating before removal. A device according to thepresent invention will generally have the burnishing mechanism withinabout 10 to about 40 cm of the rear of the scrubbing mechanism.Preferably the leading edge of the burnishing mechanism is within about25 cm from the point of bulk liquid removal and preferably within about10 cm.

The cleaning machine according to the present invention will oftentraverse the floor at the rate of about 45-55 cm per second. Theplacement of the burnisher closely following the scrubber in the deviceof the present invention will ensure that the burnishing takes placewithin about three quarters of a second after completion of scrubbingand less than about one-half second after the removal of bulk liquidwhile the coating still contains substantial absorbed water and is stillin the softened, plastic state when burnished. This will also ensurethat the device is small enough to operate in the intended cleaningenvironment.

Yet another factor that may contribute to the surprising results of thepresent invention is the use of a relatively soft brush as the mainscrubbing element. The scrubbing pads in conventional scrubbers aregenerally nonwoven pads which are quite aggressive in order to clean thecoating and in so cleaning they remove a portion of the coating leavingit in a “damaged” state, e.g., having lower gloss than before thescrubbing operation. It is counterintuitive to expect a softer brushwould provide improved floor coating maintenance. However a softer,bristled brush appears to clean effectively yet cause relatively littleloss of gloss in the polymer coating. This results in the burnisherhaving to do less work to “repair” the damage caused by the scrubbing.As a result, the burnisher can achieve a higher level of gloss with agiven amount of energy input. The use of a cylindrical, bristled brushis the preferred scrubbing element in the practice of the presentinvention. A cylindrical brush permits the construction of a morecompact cleaning device. Further, performance is enhanced because such abrush causes substantially linear striations in the floor coating ratherthan the random striations caused by a rotating, circular non-woven padas is conventionally used. It appears that these linear striations mayresult in a surface that is more readily burnished to a high level ofgloss.

The preferred brushes for use in the present invention are brusheshaving polymeric bristles, such as polypropylene or nylon bristles. Thebristles typically range from about 0.1 mm to about 0.5 mm in diameterand most preferably from about 0.15 mm to about 0.35 mm. If they aresubstantially thicker, they are too stiff to give the best results inthe present invention. If they are substantially thinner than 0.1 mm,the bristles do not have sufficient body to clean effectively.

The burnishing pad useful in the practice of the present invention canbe any of the non-woven, polymeric, for example nylon, burnishing padsthat are commonly used. A preferred pad is a nylon pad sold by ETC ofHenderson, Inc. of Henderson, N.C. under the designation “Blue Jay”.

In the practice of the present invention it has been found that anacrylic floor coating can be cleaned and burnished with good effect bythe use of the Multi-operation cleaning device and method of the presentinvention when compared with a conventional scrubbing and burnishingoperation. As shown in the Table below a floor cleaning method anddevice having sweeping, scrubbing and burnishing mechanisms on a singleplatform according to the present invention (Example “A”) was comparedwith a conventional process using an autoscrubbing machine andpropane-powered burnishing device (Example “B”). The device of thepresent invention (Example “A”) was used with a cylindrical soft,polymeric bristled brush having bristles about 0.35 mm in diameter androtating at 900 rpm. The machine was tested with two differentburnishing pads. The first was a conventional, nonwoven, nylon fiberburnishing pad available commercially from ETC corporation andidentified as a “Blue Jay” pad, rotating at 2100 rpm. The machine wasalso tested using a second type of burnishing pad that has been shown togive the best results with the conventional propane burnisher. Thedevice was constructed such that the front of the burnishing pad waslocated about 20 cm behind the rear point of contact of the scrubbingbrush with the floor.

The floor finish was an acrylic floor finish liquid available under thePremia brand, a widely used acrylic polymer floor finish commerciallyavailable from Johnson Wax Professional of Sturtevant, Wis. The washingliquid was Accumix UHS cleaner also commercially available from JohnsonWax Professional and used at a dilution of 1 ounce per 8 gallons ofwater (1 part cleaner per 1024 parts water).

The conventional equipment (Example “B”) was a conventional sweeping andscrubbing machine using a nylon bristle scrubbing pad (Red pad) widelyused in the industry and using the same scrubbing liquid as identifiedabove. The burnisher was a conventional 27 inch (69 cm) propaneburnisher manufactured by A. L. Cook and using the same Gorilla Liteburnishing pad as used on the device of the present invention androtated at 2000 rpm. The test floor was first scrubbed to simulate thewear of normal traffic and to provide a base line gloss measure and thenthe test was performed. The test floor was then scrubbed in theconventional manner with an autoscrubber using red pads traversing thefloor at a speed of 1.5 feet per second (46 cm per sec). After waitingone-half hour after scrubbing (which is a representative delayexperienced when a single operator first scrubs and then burnishes areasonable sized floor) the floor was then burnished with the propaneburnisher moving at the rate of about 2 feet per second (61 cm persecond). The gloss was measured using a Gardner 20 degree gloss meterand the readings are shown in the Table below. Separately, the testfloor was again scrubbed to establish a baseline and then scrubbed andburnished with the cleaning device of the present invention traversingthe floor at the rate of 1.7 feet per second (52 cm per second). Theaveraged measurements are shown in the Table. TABLE 20 DEGREE GLOSSMEASUREMENT Same Pads - Test 1 Unique Pads - Test 2 Example “A” Baseline32 26 Final Gloss 71 77 Increase 39 51 Example “B” Baseline 31 25 FinalGloss 64 57 Increase 33 32Test 1 = Both burnishers using “Gorilla Lite” padsTest 2 = Propane Burnisher using Gorilla Lite pad and Example “A” using“Blue-Jay” pad.

These tests show that the 20 degree gloss is 5 to 10 points higher usingthe method and device of the present invention (Example “A”) compared toa conventional scrubbing and burnishing operation (Example “B”). Thisresult is true even in Test 1 where the burnishing pad which performsbest in the conventional propane burnisher is used in both machines.Test 1 shows that the increase in gloss above the baseline by the methodand device of the present invention is 6 points better than theconventional process. In Test 2 where the best pad for each burnisher isused, the device of the present invention obtained 51 points increase ingloss versus 32 points increase for the conventional process andachieved a gloss rating of 77 versus 57 for the conventional process.

It is to be understood that while the invention has been described inconjunction with the detailed description thereof, the foregoingdescription is intended to illustrate and not limit the scope of theinvention, which is defined by the scope of the appended claims. Otheraspects, advantages, and embodiments are within the scope of thefollowing claims.

1. (Cancelled)
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 8. (Cancelled)
 9. (Cancelled)10. (Cancelled)
 11. (Cancelled)
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 13. (Cancelled) 14.(Cancelled)
 15. (Cancelled)
 16. A method of cleaning and burnishing apolymeric coating on a floor surface comprising scrubbing the floorusing a composition comprising water, wherein the scrubbing comprisesusing a bristled brush and causing the bristles to contact the floor ina substantially straight path and thereafter burnishing the floor.
 17. Amethod of cleaning and burnishing a polymeric coating on a floor surfacecomprising scrubbing the floor using a composition comprising water,permitting the coating to absorb an additional amount of water andburnishing the floor while the coating contains said additional amountof water.
 18. The method of claim 17 wherein said polymeric coating ishydrophilic.
 19. A method of burnishing a polymeric coating on a floorsurface which comprises burnishing said coating while the coating is ina softened state.
 20. A method of burnishing a polymeric coating on afloor surface which comprises burnishing said coating while the eatingcontains substantial absorbed water.
 21. (Cancelled)
 22. (Cancelled) 23.(Cancelled)
 24. (Cancelled)
 25. (Cancelled)
 26. (Cancelled) 27.(Cancelled)
 28. (Cancelled)
 29. (Cancelled)
 30. (Cancelled)
 31. A floorcleaner comprising: a sweeper assembly including at least oneretractable, rotatable sweeper brush for sweeping the floor; a scrubberassembly including at least one retractable, rotatable scrubber head, asource of cleaning fluid, and a vacuum source for cleaning the floor; aburnisher assembly including at least one retractable, rotatableburnishing pad for burnishing the floor and, a control system receivingas an input at least a cleaning mode command, the control systemincluding circuitry configured, in response to the cleaning modecommand, to automatically provide signals which: cause the sweeper brushto rotate and lower, cause the scrubber head to rotate and lower, causethe source of cleaning fluid and the vacuum source to operate, and,cause the burnishing pad to rotate and lower in accordance with apredefined sequence.
 32. The cleaner of claim 31 further including atleast one rotatable drive wheel and wherein the control system furtherincludes circuitry configured to cause the drive wheel to rotateautomatically in response to receiving a drive command to engage thedrive wheel.
 33. The floor cleaner of claim 32 of which the controlsystem further includes circuitry configured, in response to the absenceof either the cleaning mode command or the drive command, to providesignals which first cause the source of cleaning fluid to turn off andthen, after a time delay, cause the vacuum source to turn off, and causethe scrubber head to stop and raise.
 34. The floor cleaner of claim 31in which the control system circuitry, in a predefined sequence,provides signals which cause the sweeper brush, the scrubber head andthe burnishing pad to raise and stop, and cause source of cleaning fluidand the vacuum source to stop operation automatically in response of theabsence of the cleaning mode command.
 35. A floor cleaner comprising: aretractable sweeper assembly including at least one rotatable sweeperbrush, a sweeper brush motor for rotating the sweeper brush, and asweeper assembly motor for raising and lowering the sweeper brush; aretractable scrubber assembly including: at least one rotatable scrubberhead, a squeegee assembly proximate the scrubber head, a scrubber headmotor for rotating the scrubber head, a scrubber assembly motor forraising and lowering the scrubber head and me squeegee assembly, acleaning fluid pump for supplying cleaning fluid proximate the scrubberhead, and a vacuum source including an inlet proximate the scrubberhead; a retractable burnisher assembly including: at least one rotatableburnishing pad, a burnishing pad motor for rotating the burnishing pad,and a burnisher assembly motor for raising and lowering the burnishingpad; and a control system including circuitry configured, upon command,to automatically, selectively energize and deenergize the sweeper brushmotor, the sweeper assembly motor, the scrubber head motor, the scrubberassembly motor, the cleaning fluid pump, the vacuum source, theburnishing pad motor, and the burnisher assembly motor in accordancewith preselected sequence.
 36. A floor cleaner comprising: at least tworetractable head assemblies each including at least one rotatable head;and a control system including circuitry configured to automaticallyprovide signals for lowering both head assemblies and rotating bothheads upon the receipt of a command and in accordance with a predefinedsequence.
 37. The floor cleaner of claim 36 in which one saidretractable head assembly includes a scrubber brush, a squeegee assemblyproximate the scrubber brush, a source of cleaning fluid, and a vacuumsource.
 38. The floor cleaner of claim 37 in which the control systemcircuitry provides signals which cause the scrubber brush and thesqueegee assembly to lower, and which begin the operation of thescrubber brush, the source of cleaning fluid, and the vacuum sourceautomatically upon the issuance of only a single command.
 39. The floorcleaner of claim 37 in which the control system circuitry providessignals which cause the scrubber brush and the squeegee assembly toraise and which stop the operation of the scrubber head, the source ofcleaning fluid, and the vacuum source automatically upon the issuance ofonly a single command.
 40. The floor cleaner of claim 39 in which thepredefined sequence includes providing signals which stop the operationof the source of cleaning fluid before the squeegee assembly is raisedand the vacuum source is turned off.
 41. A floor cleaner for cleaning afloor comprising: a scrubber for wetting and cleaning the floor, and amember being mounted for movement from a first position to a secondposition, wherein in the first position the member prevents cleaningliquid from the scrubber brush to fall on the floor and in the secondposition the member prevents the cleaning liquid from the scrubber brushto splash against at least a portion of the cleaner.
 42. (Cancelled)